Electron discharge device



Nov. 5, 1935.v

D. A. s. HALE El AL ELECTRON DISCHARGE DEVICE,

Filed Oct. 6, 1934 4 mvE/JroRs:

ATTORNEY Patented Nov. 5, 1935 UNITED STATES ATENT OFFIQE ELECTRONDISCHARGE DEVICE of New York Application October 6, 1934, Serial No.747,148

Claims.

This invention relates to electron discharge devices and moreparticularly to an electrode assembly for such devices of the powertype.

One object of this invention is to efiiciently dissipate the heatgenerated in the output electrode or anode of the device during theevacuation treatment and operation thereof so that distortion of theelectrode is prevented.

Another object of this invention is to maintain accurately the relativepositions of electrodes in tary cathode disposed within the controlelectrode or grid and resiliently suspended from one of the insulatingmembers.

In accordance with a feature of this invention,

the anode is formed of a plurality of flanged sections to increase therigidity and area thereof. More specifically, the anode may comprisesubstantially U-shaped end sections having oppositely extendinglongitudinal flanges, and intermediate channel-shaped sections havingcooperating portions secured to corresponding flanges on the endsections. The channel-shaped sections are provided with end flanges towhich the insulating members are secured.

In accordance with another feature of this invention means are providedfor accurately positioning and maintaining the position of thesuspension members for the cathode. In a specific illustration, theapices or bights of a double M-shaped filamentary cathode, which isdisposed in a medial plane of a flattened helical grid, are engaged byhook members resiliently supported from the upper insulating member. Thehook members have elongated shanks which are held in alignment by slotsin an auxiliary insulating guiding member. The slots in the guidingmember are arranged in the plane of the cathode to allow shifting of thehook members in the cathode plane to compensate for unequal expansionand contraction of the several cathode sections. However, the guidingmember prevents movement of the hook members at an angle to the plane ofthe cathode.

In accordance with afurther feature of this invention, the electrodeassembly is rigidly supported as a unit from a stem of the enclosingves- 5 sel by rigid braces which are locked in the joined flanges of theanode sections.

The invention and the features thereof will be understood more'clearlyand fully from the following detailed description with reference to the10 accompanying drawing, in which Fig. 1 is a perspective view of anelectron discharge device constructed in accordance with this inventionwith portions of the enclosing vessel and the anode broken away to showdetails of the electrode assembly more clearly;

Fig. 2 is a perspective view of the anode assembly and supportincorporated in the device shown in Fig. 1;

Fig. 3 is a detail view in elevation of the cathode and lower insulatorassembly showing the electrical connections of the several sections ofthe cathode; and

Fig. 4 is an enlarged fragmentary detail view of the suspension springassembly for the filamentary cathode.

Referring now to the drawing, an electron discharge device illustrativeof one embodiment of this invention comprises an enclosing vessel I0having coextensive coaxial stems II and I2, the inner stem terminatingin a press I3. The stems II and I2, and also the enclosing vessel III,preferably are formed of a boro-silicate glass having a high mechanicaland dielectric strength and low coeflicient of expansion, such as Nonex.A base 5 I4 is suitably secured to the end of the enclosing vesseladjacent the stems and carries a plurality of terminal prongs I5.

An anode assembly is supported from the stem II and comprises anelectrode including opposed 4 U-shaped end sections I6 and intermediatechannel-shaped sections IT. The end sections I6 are provided withintegral longitudinal flanges I8 of relatively large area extendingoutwardly and at substantially right angles to the flat portions of theend sections. The channel-shaped sections are provided with similarlarge area flanges I9 each of which is secured to a corresponding one ofthe flanges I8 as by tabs 20, integral with the flanges I9, extendingthrough apertures 2| in the flanges I8 and crimped against'the flangesI8. The end sections I6 also may be provided with a plurality ofparallel corrugations or ribs 22 for increasing the rigidity thereof.

This construction provides an anode of high rigidity and relativelylarge surface and heat radiating capacity which will maintain its formdespite the high temperatures to which it becomes heated during theevacuation treatment and operation of the device in which it isincorporated.

As clearly shownin Fig. 2, the intermediate sections I? extend beyondthe ends of the sections [6 and are provided with integral parallel endflanges or extensions 23 each of which carries a pin 24. Seated upon theflanges 23 are crossshaped insulating members 25 and 26 which are fixedto the flanges by spinning over the pins 24, the insulating membersserving as spacers and supporting members for a helical wire controlelectrode or grid 27 and a double M-shaped filamentary cathode 28.

The helical grid 2! is carried by parallel uprights or rods 29 and 3E!extending between the insulating members 25 and 26. The upright or rod29 may extend loosely through slightly oversized apertures in theinsulating members 25 and 26. The upright or rod 30 may be fittedloosely in slots 3| in corresponding arms of the insulators 25 and 26.This construction allows lateral and longitudinal expansion andcontraction of the helical grid 21 so that distortion of the grid isprevented and the proper form and position thereof is maintained.

The ends of the preformed filamentary cathode 28 are secured to hookmembers 32 carried by a rigid tie wire 33 having arms 34 extendingthrough the lower insulator 26, and the midpoint of the cathode isengaged by a hook member 35 extending through the insulator 26 andaffixed to the tie wire 33. The centers of the two M-shaped sections ofthe cathode 28 are engaged by hook members 36 individually secured torigid U- shaped wires 31 carried by the lower insulator 26.

Thefilamentary cathode 28 preferably is disposed in a medial plane ofthe flattened helical grid 21. As is known in the art, it is desirablethat the variation in the spacing between the cathode and the grid bevery small. However, when the electrodes are thus closely spaced, thereis danger, due to the fact that the cathode may expand and contractnon-uniformly during operation, of causing a short-circuit between thecathode and grid wires. In accordance with a feature of this invention,this is overcome by supporting the cathode so that the apices or bightsof the cathode may shift in the plane of the filament but cannot shiftat other angles to this plane. The apices or bights of the cathode areengaged'individually by hook members 38 which have elongated shanksextending through slightly oversized apertures 39 in the upperinsulating member 25. The hook members 38 are supported individually byhelical compression springs to seated in recesses or pockets 4! in theinsulator 25. An insulating guiding strip 42, for example of mica,having a plurality of spaced elongated slots 43, is supported above theinsulating member 25 and substantially parallel thereto by a pair ofpins or posts 44, to which it is secured by eyelets 45. The pins orposts 44 are provided with integral flanges or collars t6 seated uponthe insulating member 25 and the lower ends 01' the posts are staked tosecure them to the insulating member 25. The slots 63 are disposedcoplanar with the filamentary cathode 28 and in alignment with theapertures in the insulating member 25 and allow shifting of the hooks 38in this plane to compensate for unequal expansion and contraction of theseveral filament sections.

However, the strip 42 prevents movement of the hook members 38 at anyangle to this plane so that the cathode cannot make contact with thecontrol electrode or grid 21.

It will be apparent from the foregoing that 6 the several electrodes maybe fabricated in a unitary assembly. This assembly may be supportedrigidly from the stem II by a pair of inverted U-shaped frames 4'! which.are affixed to parallel collars or hands 48 clamped about the 10 stem II. Each of the frames 4'! carries two pairs of converging braces 49 and50 which are suitably secured, as by welding, to the frames at one end,and are mechanically locked to the joined flanges I8 and I9 at the otherend by 15 hook terminations. This construction provides a rigid supportwhich will not allow excessive vibration of the electrode assembly.

A leading-in connection for the anode may be established through aconductor 5| which is 20 sealed in the side of the stem l2 and securedto one of the frames 41, or to another suitable portion of the anodeassembly, and to one of the terminal prongs l5. This disposition of theconductor 5! provides a long insulation path between the leading-inconductor for the anode and the conductors for the other electrodes.Although the conductor 5! has been shown as sealed in the stem 12, itmay be sealed in the stem II at a point below the lower collar or band48. A conso ductor 52 embedded in the press it is connected to theupright or rod 29 and to one of the terminal prongs I5 and serves as asupport and as a leading-in wire for the control electrode or grid 27.The heating current for the filamentary 35 cathode 28 may be suppliedthrough conductors 53 extending from the press l3 and connected to theU-shaped bent wires 3'! and to two of the prongs l5.

In order to prevent excessive heating of the 4,0 helical springs 49during the outgassing treatment of the electrodes, an insulating discmay be provided between the lower end turns of each of the springs, asdescribed more fully and claimed in the copending application of JamesE. 45 Clark, Serial No. 747,174, filed Oct. 6, 1934.

Althougha specific embodiment of the inven- -tion has been shown anddescribed, it will be understood,of course, that modifications may bemade therein without departing from the scope 50 and spirit of thisinvention as defined in the appended claims.

What is claimed is:

1. An electrode assembly comprising 9. rectangular anode formed ofopposed U-shaped end 55 sections having flanges, parallel centralchannel sections joined to the respective flanges of the end sectionsand having end flanges projecting outwardly to form supporting surfaces,a spacing member secured to said-end flanges, and 60 another electrodelocated within said anode and carried by said spacing member.

2. An electrode assembly for an electron discharge device comprising anelectrode including H oppositely directed U-shaped end sections hav- 05ing longitudinal flanges and intermediate sections having longitudinalflanges, corresponding flanges on said end and intermediate sectionsbeing joined together, a collar adapted to be fixed about a stem of saiddevice, and means 70 supporting said electrode from said collarincluding a plurality of pairs of brace members, each of said pairsbeing secured to corresponding joined flanges at spaced points.

3. In an electron discharge device, a stem, a 76 electrode havingopposed U-shaped end sections and intermediate channel-shaped sectionsjoining said end sections, said intermediate sections having flanges atone end, an insulating member seated upon said flanges, and anotherelectrode supported from said insulating member.

5. An electron discharge device comprising a hollow electrode includingU-shaped end sections and intermediate channel-shaped sections joined tosaid end sections, said intermediate sections having flanges at oppositeends, insulating members extending across opposite ends of saidelectrode and secured to the end flanges, and another electrodesupported between said insulating members.

6. An electron discharge device comprising a flattened cylindrical anodeincluding U-shaped end sections having longitudinal flanges'and parallelintermediate sections having flanges secured in face to face relationwith the respective flanges of said U-shaped sections, said intermediatesections having parallel projecting portions at opposite ends,insulating members at opposite ends of said anode and rigidly aflixed tosaid projecting portions, and a filamentary cathode extending betweenand supported by said insulating members.

'7. In an electron discharge device, a multisection filamentaryelectrode, means supporting said electrode at one end, an insulatingmember adjacent the other end of said electrode, a guiding strip carriedby said insulating member, said guiding strip and said insulating memberhaving aligned apertures, and a plurality of hook members individuallyengaging the sections of said electrode and extending through saidapertures, certain of said apertures being elongated to allow shiftingof said hook members in one plane.

8. In an electron discharge device, a filamentary cathode having aplurality of sections disposed in a common plane, means rigidlypositioning said sections at one end, a plurality of hook membersindividually engaging said sec tions at the other end, an insulatingmember 5 having guide apertures through which said hook members extend,and an insulating strip carried by said insulating member and havingelongated slots for receiving said hook members, said slots beingdisposed in said plane. 10

9. An electron discharge device comprising an enclosing vessel having astem, an anode of flattened cylindrical form having parallel centralprojecting portions, an insulating member rigidly attached to saidparallel projecting portions 15 at each end of said anode, a supportingstructure on said stem, a plurality of braces extending from saidsupporting structure to said anode, said braces having hook portionslocked to said anode, a cathode including a plurality of flla- 20mentary sections within said anode, a plurality of suspension hooksengaging said filamentary sections, resilient means on one of saidinsulating members secured to said hooks, and common guiding meanssuperimposed on said insulating 25 member and having elongated slotsthrough which said hooks extend beyond said resilient means.

10. An electron discharge device comprising an enclosing vessel having astem, an anode of flat- 30 tened cylindrical form having parallelcentral projecting portions, insulating members rigidly attached to saidparallel projecting portions at opposite ends of said anode, asupporting structure on said stem, a plurality of rigid wires extendingfrom said supporting structure to said anode and provided with hookportions engaging the central projecting portions of said anode,

a cathode including a plurality of filamentary sections within saidanode, a plurality of sus- 4o pension hooks engaging said filamentarysections, resilient means on one of said insulating members secured tosaid hooks, and a guiding strip supported parallel to said oneinsulating member and having slots in which said hooks a register topermit limited shifting movement thereof in a plane common to saidfilament sections.

DOUGLAS A. S. HALE.

VICTOR L. RONCI.

